Virtual Fence Offers High-Tech Herding

The American west is crisscrossed with fences of barbed wire that mark ranchers’ lands and keep the cattle on the right property. The problem is that while the fences work well to contain cows, they don’t encourage the animals into better pastures. The result is inefficient land use.

That’s where Dean Anderson, a US Department of Agriculture research animal scientist, comes in. He wants to build a system of virtual fences that would guide cattle to areas with more water or better forage. Each animal would be tagged with a wireless device that makes noise or gives a mild electric shock. A cow or bull that walked to the edge of the “fence” would get a little electronic nudge to drive them in the other direction.

“The number one problem in ranching is animal distribution,” Anderson told Discovery News. “You have to have he correct number of mouths on the range. The second biggest thing is getting the correct number of animals to move around the landscape.”

Ordinarily cowhands are used to drive cattle to different parts of a ranch, but that gets labor-intensive pretty quickly. On top of that, fencing hundreds or thousands of acres is expensive, both to install and maintain. Anderson saw the need for something else.

The shape of the “fences” could be adjusted remotely, using a laptop linked to GPS satellites. A rancher could set up a simple rectangle, but sometimes there might be better forage in one area and poisonous weeds growing in another. In that case, the shape of the fence could be changed to guide the cattle to the best areas for grazing. So, if a rancher noticed there is a nice patch of water near some good grass, she could get the cows to go there. If she needed to give some part of the land a “rest” she could adjust the boundaries yet again.

There’s more that this could do, though. It’s possible to get data from the animals as well – to see which ones respond better to direction, at first. Beyond that, it would mean ranchers could share tracts for grazing without worrying about mixing herds up.

Virtual fencing won’t eliminate the need for real fences. If a cow really wants to go somewhere, she will. But cattle and sheep form herds, and they tend to follow leaders. “You can accept a leaky boundary,” Anderson said. “But you only need to instrument the leaders.” If you really need to keep a cow away from someplace like a highway, a real fence is still needed.

The technology hasn’t been commercialized yet. There are still a number of issues to work out, such as how to power the devices on the cows and making them cheap enough to be practical for daily use. One possible design, Anderson said, would look a bit like cow-earmuffs.

But it is an idea that could be as big a change to and management as fencing the rangelands was a century ago.